An Overview of Different Methods for Aminoglycoside Residue Determination

Aminoglycosides (AGs) are chemical substances that exist in the bacteriologic category of traditional antibiotic (AB) therapy. The importance of the determination of AG as has been described in many situations by researchers. Because of the narrow therapeutic ranges of AGs, considerable efforts have been attributed to the analysis of AGs in pharmaceutical preparations, serum, and urine specimens for therapeutic drug monitoring purposes. Residues of ABs in many different cases like environment and human food, causes a major concern, as prolonged exposure to ABs is a serious health hazard, related to both side effects of prolonged use and the risk of developing bacterial resistance to various ABs. The major challenge is finding a sensitive and reliable method to determine AGs in a complex matrix. The microbiological assay was a simple and Review Article Morovatdar et al.; JPRI, 33(28A): 1-30, 2021; Article no.JPRI.67540 2 old method for the determination of AGs. Chromatography and spectroscopy methods are the main instrumental methods for analysis that have been employed for these purposes. Biosensor based instrumental systems have been recently used to determine the AG residues in many cases. Each of these methods has its advantages and disadvantages. This review summarizes different ways (microbiological methods, instrumental methods, and biosensor) for the determination of AGs in all cases. Different databases including PubMed, Scopus, and Web of Science with the words of AGs determination and related words for antimicrobial keywords searched without time limitation.

old method for the determination of AGs. Chromatography and spectroscopy methods are the main instrumental methods for analysis that have been employed for these purposes. Biosensor based instrumental systems have been recently used to determine the AG residues in many cases. Each of these methods has its advantages and disadvantages. This review summarizes different ways (microbiological methods, instrumental methods, and biosensor) for the determination of AGs in all cases. Different databases including PubMed, Scopus, and Web of Science with the words of AGs determination and related words for antimicrobial keywords searched without time limitation.

INTRODUCTION
Aminoglycosides (AGs) are potent, broadspectrum antibiotics (ABs) that have been used extensively in clinical and consisting of various molecules including gentamicin, tobramycin, amikacin, plazomicin, streptomycin, neomycin, and paromomycin [1]. These ABs have been used either alone or as part of combination therapy for the treatment of serious infections caused by aerobic Gram-negative bacteria. They also in combination with other ABs have been used for the treatment of selective Gram-positive infections [2,3]. Additionally, AGs have been used for other infectious diseases such as protozoa (paromomycin), Neisseria gonorrhea (spectinomycin), and mycobacterial infections (tobramycin, streptomycin, and amikacin) [4,5].
The antibacterial activity of AGs is related to the binding to the aminoacyl site of 16S ribosomal RNA (rRNA) within the 30S ribosomal subunit. They show pronounced advantages such as a rapid bactericidal activity, synergistic activities with β-lactams, and other cell wall-active agents. They also have been shown significant postantibiotic effects, while the persistent suppression of bacterial growth is observed up to 7.5 h after the drug has been cleared. These effects are related to both Gram-negative bacilli and Staphylococcus aureus, but not other Grampositive cocci [6,7].
AGs are weakly base compounds with polyatomic nature; they are soluble in water and insoluble in organic solvents, and also stable and difficult to decompose. They are characterized by two or more amino sugars linked by glycosidic bonds to an aminocyclitol component and the whole structure containing many free hydroxyls and at least two amino groups (structural formulas see Fig. 1) [8,9]. The polycationic nature leads to the poor Oral absorption, poor penetration into the cerebrospinal fluid, bronchial secretions, biliary tree and a rapid renal clearance which concentrate very efficiently within the urine. The polycationic charge may also contribute to the nephrotoxicity of AGs [4,10,11].
Because of the broad-spectrum activities and good therapeutic effect, AGs have been used extensively in veterinary medicine and play an important role in the prevention and treatment of animal diseases and also used as feed additives for growth promotion of animals [12,13].
The residues of AGs in animal edible tissues, which due to improper or over-use, may cause harm to the human, such as ototoxicity and nephrotoxicity and environment [14,15]. The other potential problem with AGs is related to the fact that AGs cannot be completely absorbed by the organism and therefore the unabsorbed ABs will not be filtered into groundwater or surface water which finally leads to environmental water pollution [16]. Additionally, the development of AB resistance in bacteria has direct connections with all of them and the relationship between veterinary use of ABs and antibacterial resistance in humans has been a subject of much concern [17,18]. Hence, accurate determination of the residues of AGs is of huge importance [9,19]. This paper reviews different methods for the determination of AGs in various matrices.

MATERIALS AND METHODS
This review evaluates and compares researches on AGs residues determination in different samples in published literature from PubMed, Scopus, Electronic Journals Library, Global Health Databases, and Google Scholar.

Amikacin
Amikacin is a semi-synthetic antimicrobial compound that is derived from kanamycin A [20]. Amikacin is particularly effective in many serious diseases caused by Gram-negative bacteria that resistant to other AGs [21]. U+Babends et al. (1955) compared the agar-well diffusion technique and high-performance liquid chromatography (HPLC)-ultraviolet (UV) detector for the determination of amikacin in human serum. The results of in vivo Analysis were similar to those of microbiological tests [22]. In another instrumental method LC with fluorescence detector could detect amikacin with a limit of detection (LOD) and quantification (LOQ) values of 0.05 and 0.1 µg/mL, respectively [23].
In another study, amikacin in the presence of other AGs in pure form and some pharmaceutical preparations was analyzed by Lanthanide Ion Probe Spectrofluorometry (LIPS). The result of the study showed there was not any significant difference between LIPS and fluorimetric method, whereas LIPS is more useful than fluorimetric in the industry because it has no interaction with other ingredients and is more rapid and simple than fluorimetric method [24]. Another method that has been used in both industry and clinical laboratory is the fluorimetric method. This method can detect kanamycin, neomycin, and tobramycin with LOD of 10.0 ng/mL [25] and fluorescence spectrophotometer quantify amikacin with LOQ of 400.0 µg/mL, that is a poor method for the determination of amikacin now [26] but in 2019 a specific fluorometric depend on molecularly imprinted polymer on high fluorescent g-C3N4 quantum dots method was developed. The LOD values of this method were lower than the previous one (LOD was 1.2 ng/mL), so this method is a reliable method for clinical monitoring [27].
HPLC with Resonance Rayleigh Scattering (RRS) was used for the detection of amikacin, netilmicin, and gentamicin with very low LOD values. This method is validated because of high sensitivity, simplicity, low cost, and lack of interference and could be used for serum and urine sample analysis in hospitals [28] and Electrospray-Ionization Mass Spectrometry (ESI-MS) also, can be used for clinical monitoring. The linear dynamic ranges of detection for amikacin was 10.0-1000.0 ng/mL [29].
Fourier-Transform Infrared (FTIR) derivative spectroscopy method provided a simple and easy method for sulfate counter ion of amikacin in pharmaceutical products with good accuracy, precision, and LOD value was 0.4 mg/mL [20]. Ultra-High-Performance Liquid Chromatography -Charged Aerosol Detector (HPLC-CAD) (2017) is a specific method for the determination of amikacin in solutions. The LOD and LOQ values were 2.0 µg/mL and 5.0 µg/mL, respectively [30].
Liquid chromatography with tandem mass spectrometry (LC-MS) (2017) was developed for the determination of amikacin in milk, honey, and pork samples. The LOD and LOQ values were 11.0 µg/kg, 33.0 µg/kg in milk and honey respectively, and 12.0 µg/kg, and 40.0 µg/kg respectively in pork sample [31]. LOQ for liver, kidney, muscle and fish sample were 5.0 µg/kg, 1.0 µg/kg, 1.0 µg/kg, 2.0 µg/kg, respectively [32]. In 2020 the dummy Molecularly Imprinted Solid-Phase Extraction (MSPE) coupling with hydrophilic interaction-HPLC with MS was developed for the determination of every AGs in water sample with the lowest concentration (LOD was 0.006 to 0.6 ng/mL) [33].
Hydrophilic interaction MSPE combined with HILIC-MS/MS was developed for the determination of amikacin in a meat sample with LOD of 2.0 µg/kg and LOQ of 7.3 µg/kg [34].
By the colorimetric method, AGs could be detected in milk or pharmaceutical products with LOD value of 0.999 ng/mL [35]. Amikacin also was detected in human serum, with a molecularly imprinted SPR sensor method (LOD 0.0025 µg/mL and LOQ 0.01 µg/mL). This method is rapid and sensitive for the determination of AGs in therapeutic ranges [36] and in the industry was used for simultaneous determination of netilmicin, tobramycin, lincomycin, kanamycin, and amikacin with LOD lower than 2.2 μM except for lincomycin that is 6.7 μM [37]. The most selective method for the detection of amikacin, gentamicin, and tobramycin are colorimetric methods based on the aggregation of gold nanoparticles (0.999 ng/mL).
Amikacin is an AG that is used in cases of resistance to gentamicin. The biosensor method is a novel method that has been used to a considerable extent to determine the amount of amikacin, but the recent instrumental method has good improvement and they are more sensitive than the biosensor method, therefore, it can be used instead of expensive and difficult methods. Generally, the microbiological assay can be used as an analysis for any laboratory due to its ease of operation and may be able to replace device methods. A comparison of different methods of determination of amikacin residues was illustrated in Table  1.

Gentamicin
Gentamicin has been used extensively to combat both Gram-negative and positive bacterial infections [43,44]. Barends  with Staphylococcus epidermidis as a selected microorganism to determine gentamicin in raw material, injectable solution, and dermatological cream with 3 different kinds of design assay (3 x1, 2x2, and 5x1). These three design didn`t show any significant difference and each design was used for a specific condition, for example, the 2 x 2 assay was used for research and both the 5 x 1and 3 x 1 designs were the most suitable assays for the routine analysis in quality controls in the laboratory [47].
Researchers compared the microbiological method (the organism tested was Staphylococcus for framycetin and B. subtilis for other AGs ABs) with TLC and HPLC-fluorimetric detector in pharmaceutical preparations for determination of gentamicin, tobramycin, sisomicin, diebekacin, framycetin, kanamycin, and netilmicin.
In 1997, HPTLC with fluorodensitometric was used to determine gentamicin in plasma and urine. The results indicated that the method was a reliable and valuable technique for quantitative analysis of the bulk drug gentamicin and gentamicin from urine and plasma samples [56].
Capillary electrophoresis electrochemical (CE-EC) was developed for the determination of gentamicin in pharmaceutical preparations with LOD of 9.1 µM [57].
In another article, the ELISA method was good for the determination of gentamicin in milk and kidney with LOD < 0.01 mg/L <0.05 mg/kg, respectively (Also neomycin, streptomycin, and DH streptomycin can be detected by this method in milk and kidney). In comparison with explained methods, the ELISA method has a long distance from MRLs [58].
The determination of gentamicin via enzyme immunoassay method in pharmaceuticals and food was done in 2002. The LOD of this method was 1×10 -9 mg/ml and gentamicin could be detected in less than 20 minutes [59]. In another study, gentamicin nanoparticle was employed with the LOD value of 0.35 ng/ml. The selectivity and sensitivity of the method were remarkably improved for gentamicin in pharmaceuticals and food [35].
Gentamicin is one of the most widely used AGs for the treatment of infectious diseases. Most reports to determine the amount of gentamicin are the instrumental method, which is both faster than the microbiological assay and less expensive than the biosensor method. In some cases, the microbiological assay can replace the instrumental method with the same sensitivity. A comparison of different methods of gentamicin residues determination is shown in Table 3.

Isepamicin
The general method for the determination of isepamicin is the HPLC method with different detectors. In 1997, researchers compared microbiological, instrumental method (HPLC) and biosensor method (Radioimmunoassay) for the determination of isepamicin in human serum. The LOQ was 0.1 µg/ml for HPLC and radioimmunoassay and 0.5µg/ml for microbiological assay. The result of regression analysis shows a good relationship between these methods and they have not significant differences [60].
In 2001, Vogel et al. developed HPLC -ELSD for the determination of isepamicin in solution. The results indicated that this method was a simple and rapid assay method for the determination of isepamicin with no derivatization problems but also LOQ was sufficient enough for the quantitative assay of isepamicin sulfate and d-isepamicin [61]. In 1990, researchers used post-column derivatization with o-phthalaldehyde for determination of isepamicin with a spectrofluorometric detector that causes many problems including the creation of degradation products. The LOD value was 100 ng/ml for isepamicin in plasma and 50 ng/ml in urine and dialysate [62]. Both explained assay methods can be used for the measurement of other AGs like gentamicin, kanamycin, etc [61,62].
Also, isepamicin was determined in human serum and rat plasma with HPLC-Fluorescence detector and HPLC-RRS respectively. The results of these methods show that they can be used instead of each other [63,64].
An instrumental method has been the main method for measuring isepamicin but for simplicity in measuring this AG, it is better to use microbiological assay. With the increasing use of isepamicin, a variety of biosensor methods may be developed. A comparison of different methods of isepamicin residues determination is illustrated in Table 4. LC-MS/MS was used for the detection of kanamycin in anatolian buffalo milk with LOD of 3.56 μg/kg [66]. Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS) was used for the determination of kanamycin in pork meat with LOD and LOQ of 3.3 µg/kg and 10.9 µg/kg, respectively [67].
An unmodified silver nanoparticle method was employed for the determination of kanamycin in milk with LOD of 2.6 ng/ml which was much lower than MRL [68].
The gold nanoparticle was the most sensitive method for the determination of kanamycin in aqueous solutions (LOD was less than 0.1 nM). This method was used for analyzing milk or meat samples [69]. Aptamer-immobilized electrospun nanofiber membranes with signal probes conjugated gold nanoparticles was described for the determination of kanamycin with LOD 2.5 nM in drinking water and milk samples. These articles show that kanamycin could be evaluated with gold nanoparticle at very low levels [70]. In another study chlortetracycline-coated silver nanoparticles-(UV) spectroscopy detect kanamycin in aqueous solution with LOD values in 120-480 picomolar [71].
Photoluminescence response of an off-on probe based on the spherical gold nanoparticles method was used to determine kanamycin in yellow-fever vaccine and veterinary pharmaceuticals and medical compounds. The LOD and LOQ values were 0.06 µM/mL and 0.2 µM/mL, respectively [72].
As previously explained, the instrumental method is usually for the determination of AGs, and the usual method used for the determination of kanamycin in the food sample was the LC-MS method. Biosensor methods that have been used for the determination of kanamycin have good sensitivity and selectivity. Table 5 showed the comparison of different methods of kanamycin residues determination.

Neomycin
There is one microbiological method for the determination of neomycin that is used in multiple systems. The LOD of this method was 2. RNA aptamers detected neomycin in the range of µM in solutions [75]. ssDNA method was successfully applied for the detection of heavy metal mercury (II) ion (Hg 2+ ) and silver (I) ion (Ag + ) and AG ABs residues in food [76].
Because the biosensor method is new, few articles have been existed to measure neomycin in different samples. The instrumental method is a both sensitive and available method. Modified-RNA aptamer-based sensor detects neomycin in the submicromolar range. Table 6 Compares the different methods for neomycin residues determination in various samples.

Sisomicin
For the determination of sisomicin, limited methods have been developed. In one study, Broughton et al. (1976) compared two types of quantification methods (radioimmunoassay and microbiological assay) in the human serum. In the microbiological assay, the agar well diffusion method was used and Klebsiella was set as the test organism. The result of radioimmunoassay showed the sensitivity as 140 pg/mL and in comparison with the microbiological assay, there were not significant differences [77] also, microbiological assay did not show any significant difference with TLC and HPLC-fluorescence method [48,49].
HPLC with UV and fluorescence detectors were used for clinical monitoring of sisomicin and LOD was 62.5 ng/ml [78]. Microbiological and instrumental methods have been used to determine the amount of sisomicin, and the biosensor method has been compared with the microbiological method. There are good instrumental methods for evaluation of sisomicin in the clinical monitoring and food industry and maybe the microbiological method could be used instead of chemical methods in any laboratories. The comparison of different determination methods for analyzing the sisomicin residues is shown in Table 7.

Streptomycin
Streptomycin is the first AG that was discovered in 1943 [79] and it has lots of uses in many cases (from prevention to treatment in veterinary medicine to human diseases) [80]. Streptomycin usually is in the first line of antibiotic therapy and has good effects on Gram-negative bacterial infections which occur in veterinary and human [81,82]. It also administered as anti-tuberculosis agents in the second-line for the resistant strains to isoniazid and rifampin [83]. The residues of streptomycin in animal-derived products could pose health hazards to consumers [18].  [31] streptomycin [80] but previously Han et al. [84] and Kim et al. [85] had developed UPLC-MS/MS for anti-tuberculosis drug samples and LC-MS/MS method for human serum respectively. During sample preparation for these methods, there was a decrease in polarity that has a negative effect on the detection and quantification of AGs [84,85]. LC-MS/MS was also used for the determination of streptomycin in honey with LOD of 4.7 µg/kg. This method can be used in a laboratory because it is a fast and accurate method. It also needs small sample and reagents [86]. . UPLC-MS was developed for screening drug residues in pork. The LOD and LOQ values were 0.6 µg/kg and 2.0 µg/kg respectively. Compared to the conventional quantitative method, this method could improve instrumental efficiency, thus can be applied in prompt screening for large batch samples [67]. By the HPLC-ELSD method, AG in food could be determined with LOD of 3.0 µg/kg [74].
LC-MS (2017) was developed for the detection of streptomycin and DH streptomycin in honey, milk, pork. The LOD and LOQ values for streptomycin were 4.0 µg/kg, 13.0 µg/kg in honey and 3.0 µg/kg 10.0 µg/kg in milk and 5.0 µg/kg 17.0 µg/kg in pork, respectively. LOD and LOQ were 3.0 µg/kg, 10.0 µg/kg in honey and milk, 4.0 µg/kg, 13.0 µg/kg in pork, respectively for DH streptomycin [31]. CE-MS method detected these AGs with LOD and LOQ of 0.4 µg/kg, 1.4 µg/kg, and 4.7 µg/kg,15.7 µg/kg, for streptomycin and DH streptomycin, respectively [55]. For the determination of streptomycin and DH streptomycin in food LC-MS/MS was used. The LOQ was 25.0 ng/mL and 30.0 ng/mL, respectively [32], and LC with fluorescence detector was used for the detection of streptomycin and DH streptomycin in food. LOD values were 7.5 µg/kg and 15.0 µg/kg, respectively for streptomycin and DH streptomycin [87]. LC-MS determined streptomycin and DH streptomycin with LOQ of 0.02 and 0.01 mg/kg, respectively in bovine muscle, bovine liver, milk, chicken egg, fish, and shrimp samples [51].
The colorimetric technique was developed for the determination of streptomycin with LOD 60.2 nM in raw milk. These aptamers used to detect very low levels of streptomycin [88]. By colorimetric aptasensor, streptomycin with LOD of 108.7 nM in milk and human serum could be detected [89] and by multi-color quantum dot-based fluorescence immunoassay array streptomycin was detected with LOD of 5.0 pg/mL [90]. In 2020 chlortetracycline-coated silver nanoparticles-UV spectroscopy detected streptomycin in aqueous solution with LOD 1000-11000 picomolar [71].
There is a microbiological assay method for the determination of streptomycin that may be useful for routine analysis in milk. The use of the biosensor method is expanding; as predicted in the next few years, it will replace other methods, even though it is expensive. Table 8 compares the different methods which have been used for the determination of streptomycin residues.

Tobramycin
Tobramycin is another AG that is similar to gentamicin and kanamycin in many properties such as pharmacokinetic, toxicological, and some microbiological ones [92]. Tobramycin has a good influence on Gram-negative bacteria especially many strain of the Enterobacteriaceae and Pseudomonas and also, S. aureus that have resistance against gentamicin [93]. Lamb et al. (1972) reported factors that influence the microbiological assay to find the most suitable methods for the determination of tobramycin in blood, urine, and pharmaceutical preparations. Various factors such as sample diluents, pH, molarity, iron, and sodium ions were checked and the important ones were diluents, pH, and molarity. They used three kinds of methods including the disc-plate method, turbidimetric assay, and cylinder-plate method. The tested microorganisms were B. subtilis and S. aureus for turbidimetric and cylinder-plate, respectively.
For diluents effect, the results of the article showed the sensitivity of the cylinder-plate assay was increased 10 times more than the disc assay when increasing pH, therefore the dilution factor affected more on the cylinder-plate assay. By the addition of the ionic compounds like Na + and Fe 3+ in agar base, the sensitivity of tobramycin determination was decreased even though variations in pH and ion concentration were more critical for the cylinder assay, but this assay system was more reproducible and sensitive than the disc [94]. Lode et al. (1975) used the agar diffusion method with B. subtilis as a test organism for the estimate of pharmacokinetic of gentamycin, sisomicin, and tobramycin. They concluded that because of similar chemical structures and molecular weights the pharmacokinetic parameters obtained for the three AGs did not show any significant differences [95]. Also, Hubenov et al. (2007) employed two methods for evaluating the pharmacokinetics of tobramycin with HPLC-fluorescence detection (LOQ of 0.2 µg/and LOD of 0.1 µg/mL) and microbiological assay with B. subtilis (ATCC 6633) as a test organism. The LOD and LOQ values were 0.024 and 0.048 µg/mL, respectively [96]. CE-LIF device was developed to detect tobramycin in human serum (LOD=17.1 nM). The advantages were small sample requirements and short analysis time to quantify drugs in biological samples. Also, CE-LIF detected paromomycin, bekanamycin, and kanamycin with LOD of 24.0 nM, 15.0 nM, and 14.4 nM, respectively [65].
HPLC-ELSD method was developed for the detection of tobramycin in tilapia with LOD of 3.0 µg/kg. This method could be used for the detection of residual of AGs in food [74].
Working on the determination of tobramycin with biosensor method has been started since 1997 with RNA aptamers [97], but after 9 years, the researchers were able to detect tobramycin with potentiometric measurements only in aqueous solutions [98].
In 2011 RNA aptamer for determination of tobramycin in human serum was developed. The LOD depended on the ratio of serum/buffer (LOD was between 15.0 µM and 17.0 µM) [99], but in 2019 with voltammetric sensor tobramycin could be detected in blood and human serum with LOD of 2.0 µM [100].
For milk and medicine products colorimetric method based on the aggregation of gold nanoparticles with LOD of 0.579 ng/ml was developed. This method is the most sensitive biosensor method [35], and for ophthalmic preparations, it used the visible light effect on surface plasmon resonance of gold nanoparticles with LOD of 3.8×10 -9 M, with the advantage of no chemical derivatization [101]. For the first time in 2020, dynamic aggregation of Sodium Dodecyl Sulfate (SDS)-capped silver nanoparticles have been developed for the determination of tobramycin in exhaled breath dense. LOD values for this method was 0.5 ng/mL [102].
Tobramycin is one of the most widely used AGs in the treatment of diseases. Microbiological, instrumental, and biosensor methods have been used to measure this compound, but given that the biosensor method is a new way to measure in the coming years, it is expected that more and more diverse methods will be used to determine the amount of this AG with more accuracy. The comparison between different methods of tobramycin residue determination is illustrated in Table 9. Apramycin sulfate is detected by two spectrofluorimetric methods. The first one was based on measuring the inherent native fluorescence and the second one was dependent on enhancing the native fluorescence intensity of the drug-using SDS in veterinary AB drug, pharmaceutical preparations, and milk samples. LOD values for first and second methods were 0.05 μg/mL and 0.02 μg/mL respectively [103]. LC-MS detected apramycin and spectinomycin with LOQ of 0.01 mg/kg and 0.02 mg/kg in bovine muscle, bovine liver, milk, chicken egg, fish, and shrimp [51].
Fortimicin A and 3-0-demethylfortimicin detected by HPLC-UV detector in the range of pg/mL The assay procedure was also applicable to the determination of the other AGs such as gentamicin, tobramycin, kanamycin, and amikacin [104].
Paromomycin was determined with reversedphase ion-pair HPLC separation coupled with the pulsed amperometric detector (2000) in animal feed matrices (rabbit, chicken, and pig feeds). The statistical analysis of the performance of the method demonstrated its very good reliability and allows us to propose it as the reference procedure for the determination of paromomycin in the considered matrices [105]. In 2010 HPLC-ELSD was employed in the commercial sample which the authors of the article showed that the method is reliable and repeatable for determination of paromomycin (the LOD and LOQ of paromomycin were 2.25 μg/ml and 25.5 μg/ml respectively) [ For determination of vertilmicin sulfate, arbekacin and dibekacin were developed HPLC-ELSD method that LOD of vertilmicin sulfate was 10.0 μg/mL, arbekacin was 4.5 μg/mL and dibekacin was 5.0 μg/mL [70]. The advantage of this method was the determination of AGs without any derivation [107,108].

CONCLUSIONS
AGs are one of the oldest ABs due to their good effects on Gram-negative bacteria; they are widely used in the treatment of diseases today. For this reason, the measurement of AGs in different matrices is of particular importance. Different types of methods have been developed for the determination of a wide variety of AG by microbiological, instrumental, and biosensors in various cases. The increasing number of articles published in this caption reflects a great concern in public health and drug resistance especially for gentamycin and streptomycin because of wide use in the treatment of different diseases.
Generally, based on the kind of AG, different methods have been used to determine the related residues. The microbiological assay is an old, less sensitive, and slow method (needs time of incubation). Due to that, the method is less operational and does not need a very special expert and experience, it could be used for the determination of AGs in some cases. The instrumental methods are popular methods from past to present. These methods are not only more sensitive than microbiological, but also are faster.
The biosensor method is a new one and attracts attention. The main advantages of them are higher selectivity and sensitivity in compared with conventional ones. But the main drawbacks of the biosensor method are related to the high cost and Availability of experts that make it impossible to use for every laboratory.
The first part is the determination of AGs in human serum or plasma due to the evaluated concentration of AG in the blood that patients give a proper treatment with reductions of ototoxicity and nephrotoxicity. This is especially important for streptomycin and gentamicin, the most common AGs. We predict that the device will be more sensitive and faster in the future.
The second one is, the determination of AGs in food, water, and environment that all people have always exposed and can produce drug resistance in society, therefore in this section should develop methods to separate AGs from other components.
The third one is, using different methods for the determination of AG in the industry. Like the previous part, it needs to develop methods to separate AGs from the other components.

DISCLAIMER
The products used for this research are commonly and predominantly use products in our area of research and country. There is absolutely no conflict of interest between the authors and producers of the products because we do not intend to use these products as an avenue for any litigation but for the advancement of knowledge. Also, the research was not funded by the producing company rather it was funded by personal efforts of the authors.

CONSENT
It's not applicable.